Process of impregnating paper



July 15 1924. 1,501,493

L. C. KOPLIN PROCESS OF IMPREGRATING PAPER 7 1 Filed July 6, 1921 \iqht pressure.

- -|iqhi pressure -liqht pressure v INVENTOR.

Leonard, C. KpHn ATTORNEYQ Patented July 15, 1924.

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LEONARD C. KOPLIN, F AKRON, OHIO, ASSIGNOR TO THE THOMAS PHILLIPS COM- PAN-Y, OF AKRON, OHIO, A. CORPORATION OF OHIO. A

PROCESS OF IMPREGIilATING PAPER.

Application filed July 6,

To all whom 51- may concern:

Be it known that I, LEONARD .C. KorLIN, a citizen of the United States, residing at Akron, in the county of Summit and State of Ohio, have invented certain new and useful Improvements in Process of Impregnat- 7 ing Ia'per, of which the following is a specificatlon.

This invention relates to a process of coat- 10 ing and impregnating paper for the purpose of strengthening it and rendering it suitable for use in heavy work where great toughness and durability is required. The object of the process herein disclosed is to 15. combine with the paper a toughening solution in such a manner that it will enter into the pores and fibres without simply affording a superficial coating on the paper. The process herein disclosed is particularly valuable as the paper attains or acquires a degree of stretchability or elasticity not found in prior coated or impregnated papers and it is thereby rendered extraordinarily tough and durable and articles made there-- from, such as bags or the like will withstand a degree of rough handling not possible heretofore.

Briefly stated my process comprises the coating and impregnation of the paper while it is in an open or porous and absorbent condition, so that the coating and strengthening liquid penetrates the fibres of the paper. This may be done in any preferred manner, and I have found that excellent results are obtained by running the paper through the calenders which are adjusted in a manner to permit the impregnating fluid to be absorbed by the body of the paper.

' In the drawin accompanying this appli- '40 cation I have s own an arrangement by which the impregnating process may be successfully carried out.

In this drawing the paper is designated by the numeral '1, and passes in the direction of the arrows, through a set of calen der rolls, here illustrated as a stackof five rolls numbered, 2, 3, 4, 5, and 6. The first four rolls 2, 3, 4 and 5 are so adjusted rela-. tively to each other that a. comparatively glht pressure is obtained upon the paper,

li I w ich leaves it open and absorbent. The

rolls 5 and 6 are adjusted so that aheaiy pressure is exerted on. the paper at this point. The roll 6 dips m'to a pan of the vention consi;

1921. Serial No. 482,652.

1 thorough saturation of the body of the paper is obtained, at the time of. the heavy calendering operation. The impregnating solution enters into the pores and fibres of the paper, being forced in by the heavy pressure between the last two rolls of the calender.

In former processes, it has been the custom to coat the paper merely, forming a skim or finish, which, however, does not permit the solution to become thoroughly embodied throughout the paper.

If desired, I may add a device for breaking the surface of the paper to render it more absorbent. This may be embodied in many ways, but I have elected to show a small roller 8,'the surface of which is provided with a number of fine sharp pins or prickers which may be designated as a pricking roll. The ends of the pins are designed to enter into the paper to puncture or break the surface without necessarily piercing the body of the paper. In this manner thepaper is rendered more absorbent. 1

Inv order to carry out the process satisfactorily to produce a tough, elastic'paper, I prefer to use a good manilastock and to run it through the beaters without any sizing material. 'The impregnating and strengthening material is any well known or suitable strengthening or impregnating solution, usuallya'caseln solution which is absorbed by the porous paper stock and is thoroughly squeezed into the stock by the heavy pressure between the last rolls ofthe calendelz; U m While there is shown herein a satisfactory series of -ste' s, and an arrangement of the calender rol sgto obtain a paper having the desirable qualities enumerated, it will be. understood-thati ariations in the process may be made with ut departing from the inven tion. The fpricking open of the surface of the paper before the solution is applied is advantageous, -although the invention will operate satisfactorily without this additional feature. The rincipal features of my in- {forming the paper in an I open or poro'us condition and then applyripple between the rolls 5 and 6 so that an opportunity is provided for the impregnation of the paper prior to 'the completion of the final calendering operation.

The paper obtained by the use of this process is tough and durable. It possesses a high degree of elasticity or stretchability and is not easily torn. Should the paper he fractured or torn, the tear will not spread but will be confined to a small area. The paper is especially suitable for wrapping purposes or for manufacturing bags and other containers, although its'use is not so limited. I have found that bags made from paper treated in the manner described, make excellent containers for cement, plaster or other heavy, finely powdered material The paper may be fed to the calender rolls from any suitable source or it may come directly from the drying rolls.

1. The process of manufacturing a tough, durable paper, comprising forming said paper from an unsized manila stock, calendering said paper with a light pressure so as to leave it open or porous and impregnating the paper with a casein solution under heavy pressure.

2. The process of manufacturing a tough, durable paper, comprising forming said paper from a stock without any sizing, calendering said paper with a light pressure and then with a heavy pressure and impregnating the paper with a strengthening solution and subjecting it to a heavy pressure calendering.

The process of manufacturing paper, comprising forming a sheet of unsized manila stock, calendering the-paper -with a light pressure only so as to leave it open and porous, and impregnating the paper with a casein solution by a heavy calenderin operation, whereby the solution is forced into the fibres of the paper.

4. The process of manufacturing paper, comprising calendering the paper so as to leave it open and porous, perforating the surface of the paper and then impregnating the paper with a strengthening solution under heavy pressure.

5. The process of manufacturing paper, comprising calendering the paper with a light pressure, puncturing the surface of the paper, whereby the paper is absorbent and then impregnating the paper with a strengthening solution under heavy pressure.

6. The process of manufacturing a tough, elastic-paper, comprising calendering the paper under light pressure so that it is absorbent, coating the paper While in an absorbent condition with a strengthening solution and calendering under heavy pressure.

7. The process of manufacturing a tough, elastic paper, comprising calendering paper made of an unsized stock under light pressure, so that it is absorbent, coating the paper while in an absorbent condition with a strengthening solution and calendering under heavy pressure.

8. The process of manufacturing a tough,

elastic paper, comprising calendering paper made of an unsized stock under light pressure, so that it is absorbent, coating the paper while in an absorbent condition with a strengthening solutioncomprising casein and calendering under heavy pressure.

9. The process of manufacturing a tough, elastic paper, comprising calendering a paper made of an unsized manila stock under light pressure, so that it is absorbent, coating the paper while in an absorbent condition with a strengthening solution and calendering under heavy pressure.

10. The rocess of manufacturing a tough, elastic paper, comprising calendering a paper'made of an unsized manila stock. under light pressure so that it is absorbent, coating the paper while in an absorbenttcondition with a strengthening solution containing casein and calendering under heavy pressure.

LEONARD C. KOPLIN. 

